Risk of Chagas disease through transfusions in the Americas

The safety of blood transfusion depends on a country's laws, decrees and/or regulations concerning the collection, production and use of blood and blo od derivatives. It also needs governmental enforcement of those instruments , as well as trained health professionals to obtain blood and produce blood derivatives, following total quality control procedures both at collection and production, and use. By 1998, all Latin American countries had laws, d ecrees and/or regulations that governed the production and use of blood, wi th the exception of El Salvador and Nicaragua. During the past six decades, economic need in Latin America has promoted migration to urban areas. Cons equently, at present time, more than 60% of the population live in cities, which increases the probability of finding blood infected by Trypanosoma cr uzi among donors. Unless all the blood from infected donors is discarded, t he possibility of transmitting infection by transfusion remains. Moreover, infection by T. cruzi through transfusion is a potential problem in develop ed countries, now that tens of thousands of individuals from Latin America have migrated to the United States, Canada, western Europe, Australia and J apan. When donors are not screened for T, cruzi, the risk of transfusing in fected blood is greater at higher prevalence rates of infection in the dono r population; it also increases with the number of transfusions received by the recipient. In 1993, Bolivia presented the highest risk of receiving in fected blood and becoming infected with T. cruzi;this country was followed by Colombia, El Salvador and Paraguay. As the coverage of HIV screening bec ame almost universal, the probability of receiving blood infected by HIV an d becoming infected was low in all countries. In the case of hepatitis B (H VB), the highest probability of infection was in Bolivia, Nicaragua and Gua temala. This probability was even greater for Hepatitis C (HVC), given the low coverage of donor screening in all countries. In absolute numbers, the highest potential for occurrence of cases of T. cruzi infection were presen t in Bolivia, the greatest number of HVC cases in Colombia, and the most ca ses of HVB in Nicaragua. Only in two countries, Bolivia and Colombia, HIV c ould be potentially transmitted by blood transfusion. Although the situatio n has improved since 1993, and 100% of donors are being screened for T. cru zi in Argentina, Colombia, Ecuador, El Salvador, Honduras. Paraguay, Urugua y and Venezuela, success will only be assured by: total enforcement of the law by governments; implementation of altruistic and volunteer blood donati ons, exclusively; 100% of donors are screened for communicable diseases; th e collection, processing and use of blood strictly follow quality control n orms; reagents used in diagnosis are adequate, and the use of blood and blo od derivatives is limited to cases where it is only absolutely necessary.